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Re: [Cfrg] Ed25519 - X25519 keypair equivalences

Russ Housley <housley@vigilsec.com> Fri, 05 June 2020 18:55 UTC

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From: Russ Housley <housley@vigilsec.com>
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Date: Fri, 05 Jun 2020 14:55:06 -0400
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To: Robert Moskowitz <rgm-sec@htt-consult.com>
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Subject: Re: [Cfrg] Ed25519 - X25519 keypair equivalences
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Bob:
> 
> I am trying to understand rfc7748 sec 4.1 last paragraph:
> 
>    The Montgomery curve defined here is equal to the one defined in
>    [curve25519], and the equivalent twisted Edwards curve is equal to
>    the one defined in [ed25519].

I think this is talking about different ways to represent the curve in an implementation.  It is not encouraging the use of the same private key for key management and signature.

Russ

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